Astronomy 4L, Section 6272, Spring 2012

05/17/12:
We started off class this week by going over last week's lab and the last quiz (average score was 12 out of 14). Next, we had a whole-class brainstorming session on all the properties of Earth that might be important for developing and sustaining life on our planet. Our lab activity this week was a discussion-style activity where everyone played the roles of different scientists asking themselves important questions about the presence of life in the universe and the probability that we'll be able to ever communicate with them. We handed in the final drafts of our observing reports, and reviewed old topics for the final exam next week. I also gave some information about the partial solar eclipse this Sunday.

05/10/12:
I went over last week's lab and gave everyone some general feedback on the lab report rough drafts at the beginning of class today, and then we took our sixth and final quiz of the semester. Next week I'll bring a grade update with the lowest quiz score dropped so that everyone has an idea of where they're at going in to the final exam. After taking the quiz I introduced our two activities. We used Newton's law of gravity to compare what our weight would be on the surface of each of the four jovian planets in the first activity. In the second activity, we used data from the discovery of the extrasolar planet 51 Pegasi B to learn how the radial velocity method of discovering planets worked. We plotted the radial velocity of 51 Pegasi versus time, and used Kepler's third law to determine the size of the orbit of 51 Pegasi B, along with its mass.

05/03/12:
This week I began class by going over Quiz #5, and last week's homework and lab on planetary system formation. I also went over some of the highlights from the lab that you'll need to know for next week's quiz. Next, we did a brainstorming activity highlighting the different properties of terrestrial and jovian planets, as a way to warm up for our lab studying terrestrial planet features. We did several mini-activities for our lab, each focusing on a different terrestrial planet. First we studied the orbit of Mercury and some of its surface features. Next, we compared the atmospheres of Earth and Venus by weight and composition. Then we used images of the surface of Mars to measure the size of craters and impacts, and learned how to tell the difference between mountains and valleys using shadows. I also told the class a little bit about the recent Messenger Mission to Mercury and the citizen science project Moon Mappers.

04/26/12:
We took Quiz #5 at the start of class today, and I handed back the Lunar Properties lab from two weeks ago. Next, we did another role-playing style activity, where each student played the role of an expect in some aspect of planetary science, and we worked together as a class to develop a model of how planetary systems form around stars. We did some follow-up questions to review the ideas we'd come up with for the mechanism of solar system formation. After doing the review questions, I went over some guidelines for writing the observing report rough drafts and helped out any students who wanted to go outside for another Venus observation.

04/12/12:
Today we had a substitute lead our lab activity on lunar properties.

04/05/12:
We took Quiz #4 at the beginning of class today, after I went over some points from last week's lenses and telescopes lab. Our lab this week focused on spectroscopy, the study of spectra. In our lab we used diffraction gratings and handheld spectrometers to look at fluourescent lights, incandescent lights, and gas tubes. We learned how to identify continuous, emission, and absorption spectrum types and how the properties of an object's spectrum can tell us important information about the composition and properties of that object. I also checked off the first three Venus sketches for our observation this week and gave everyone some short feedback on their observations.

03/29/12:
Today I began class by collecting the moon phases homework and introducing the news article homework (Homework #3, posted above). Our activity for this week involved learning how lenses work, and how they can be used to make simple two-lens telescopes. We measured several properties of sets of six lenses (diameter, curvature, focal length, image size, and focal ratio) and learned how these properties describe and control the features of the image formed by the lens. In the second part, we learned how the properties of two lenses work together to control the brightness and magnification of a telescope, and verified our results with our simple telescopes.

03/15/12:
I went over Quiz #3 and last week's lab at the start of class (average quiz score was 11 out of 14), then reminded everyone of the upcoming homework and project deadlines the week after spring break. Next, I did a short introduction to some robotic and manned missions we've sent into space (this was more of a highlights reel than a comprehensive list). Our activity involved role-playing as members of the UK parlaiment circa 1760, discussing whether to fund the voyage of Captain Cook to the south pacific to observe the transit of Venus. After several whole-class discussions, we related this situation to the prospect of sending a manned mission to Mars in the future and answered some review questions.

03/08/12:
I handed back the seasons lab from last week and went over the main ideas at the beginning of class, and then we took Quiz #3. Our activity for this week had two main portions. First, we built a scale model of the Earth and Moon using clay and styrafoam balls, and used that scale model to examine the positions of the Earth and Moon during lunar and solar eclipses. In the second part of the lab we recreated the measurement of the AU in kilometers using measurements from a transit of Venus. I spent a few minutes going over some upcoming eclipse and transit events as listed on NASA's eclipse website, and then we went outside to work as a class to look at Venus and work on our observation project.

03/01/12:
I went over Quiz #2 at the start of class (average score was 10/15), and talked about the main points from last week's Kepler's Laws lab. I also talked about what will be on Quiz #3 next week, and reminded everyone that we should be working on our observations of the moon phases and Venus. Our lab for this week focused on the explanation for the seasons. We tested four different hypotheses for why Earth has seasons, and made sure our model was able to explain some key observations (it's warmer in summer than in winter, and the southern hemisphere has its seasons during opposite times of the year from the northern hemisphere). I showed this demo of Earth's orbit around the Sun while everyone worked on the lab to help illustrate the changing angle between sunlight and the surface of the Earth. The demo also shows how the number of daylight hours varies from one time of year to the next.

02/23/12:
We started out class by going over our scale model lab, and then taking the second quiz. After the quiz I went over the instructions for our observation project, which are posted above. I also announced a change to our syllabus: we will have a substitute instructor teach a lab about Lunar Properties on April 12th. Our activity for this week involved studying Kepler's Laws of planetary motion. We used a scale diagram of the orbit of the Explorer 35 spacecraft to verify that the spacecraft's orbit obeyed Kepler's Laws. We were able to show that, within experimental uncertainty, Explorer 35 had an elliptical orbit, and did indeed have a faster orbital speed when it was closest to the Moon. We also measured the semimajor axis of its orbit and used Kepler's 3rd law to calculate its orbital period.

02/09/12:
I went over the answers to our first quiz at the start of class (the average score was 13.5 out of 18), and went over a few minor points from last week's lab. I also gave a short explanation of our second homework assignment, which involves observing the phase of the moon for a month. Our lab this week involved building a scale model, which we projected onto a map of the Petaluma campus. Groups were each given pairs of objects, and we scaled down the sizes and orbital distances of the planets before sharing the class data on the board. We also answered several questions regarding the locations of the various planets in the sky and relative to the Sun, using diagrams of the solar system and lists of the RA and Dec of the planets.

02/02/12:
Today we took the first quiz at the beginning of class, and then went outside to get some more practice using the star wheel and become more familiar with the night sky. Our lab activities for this week centered around the phases of the moon, Mercury, and Venus. We used styrafoam balls and the light from an overhead projector to simulate the moon phases, and determine what time of day each phase of the moon rises and sets. We also used top-down diagrams of the inner solar system to learn about the phases of mercury and venus, and made some simple calculations of the orbital period of those two planets using their phase changes.

01/26/12:
I spent the first ten minutes of class today going over last week's lab, and then did a mini-lecture on the different motions of the Earth. We talked about the differences and effects of daily and yearly motion, and I also showed this movie demonstrating precession. Our lab used a classroom-sized model of the Earth, Sun, and the constellations of the zodiac to tell us which constellations are visible at which times of the year. After everyone finished up with lab, I took us outside into the parking lot and pointed out some constellations and taught the class how to measure distances on the night sky using our hands and fingers. At the end of class I reviewed the concepts you'll want to know for our first quiz next week. You can find a vocabulary list posted above, along with the first observing homework assignment.

01/19/12:
Welcome to Solar System Lab! This week I spent some time going over the syllabus and how class will be structured. You will want to download the syllabus and ready through it carefully as soon as possible. Our activities today included learning how to use the star wheel and a refresher on using scientific notation. We also did an exercise on scientific measurement, uncertainty, accuracy, and precision. Before our next class meeting, make sure to do the Prelab questions posted above and print out the instructions for our lab on the motions of the night sky.